Inflation

[mikesbytes (Michael)]

Hi newbie here

I'm interested as to whether inflation is occurring at the same rate throughout the observable universe

[mikesbytes (Michael)]

No replies, I'm guessing my question is hard to answer? Is that the case?

[doppler (Rick)]

My guess would be that expansion is occuring at the same rate in our visible universe indicating that we have no idea in which direction the "big bang" originated.

[Nikolas (Nik)]

It all depends on what you ate the night before.........

[barx1963 (Malcolm)]

I am not a cosmologist but as I understand it, "inflation" normally refers to the very rapid expansion of the universe in the very first tiny fraction of a second after the big bang.
The universe since then has been expanding and current thinking is that the expansion is actually accelerating due to the presence of dark energy. The expansion is occurring throughout the universe. One way of thinking about it is that the universe is a four dimensional spacetime entity, but we see it as a 3 dimensional universe. Take a balloon and draw dots on its surface. As you blow it up it is expanding as a 3 dimensional entity, but from the point of view of a being on it's surface viewing in 2 dimensions, all the dots are moving away from each other. And that expansion is occurring all over the surface at the same time.
The balloon is analogous to viewing a four dimensional construct in three dimension, just deducting one dimension.
Of course this expansion is at the large scale. Locally other forces are at play. For example, the Milky Way and the Andromeda Galaxy (M31) are being pushed apart by the expansion of space, BUT that force is not as strong as their mutual gravitational attraction, so they are moving closer together.

Hope this is clear enough, and as I said I am certainly not an expert. The above is simply how I think of these matters and I am happy to be corrected by any people more knowledgeable.

Malcolm

[gregbradley]

I am not sure that this could be measurable from a fixed view on Earth.
Perhaps the average red shift of galaxies further away compared to those closer in would tell.

Greg.

[rat156]

Originally Posted by mikesbytes

Hi newbie here

I'm interested as to whether inflation is occurring at the same rate throughout the observable universe

Hi Mike,

Your question sounds simple, but is, in fact, quite complex.

The current thinking, as expressed by others here, is that the universe is in an expansion stage, rather than inflation, and that the expansion is accelerating.

This raises many, many questions. But first you need to conceptualise some very important concepts.

The Big Bang. Didn't happen anywhere, it happened everywhere, at once, because in this instant the Universe came into being. It was, in the first instance extremely small, but still contained everything in the universe today. The universe we see today is the same stuff, just expanded out in a more familiar form, with our familiar forces etc. You must try to envisage something just popping into existence, but doing so everywhere, that way, there is no origin. This raises more questions, like, when did gravity become a force in the universe? Has the gravitational force always been as strong as it is now? Without Baryonic matter (atoms etc) does gravity actually exist?

Now, you have that conceptualised, you may be able to see that everything is moving apart, with the apparent exceptions of localised phenomena, as previously explained (Andromeda). An analogy is raisons in a cake as it rises. Now consider that the rate of expansion is increasing and that the further a thing is away from us the faster it is accelerating away. There come a time/place/distance when this acceleration must, if it is consistent acceleration, then exceed the speed of light. At which point the object becomes invisible to us. So there may be more to the universe than meets the eye, literally.

If you are really interested in this subject, there are many good Cosmology resources on line, or go to a library (maybe a local Astronomical Society) and borrow some books. It is a fascinating subject of which I have only scratched the surface.

Cheers
Stuart

[mikesbytes (Michael)]

Thanks for the info guys, much appreciated.

There yah go, proof I'm a newbie, I've mixed up Inflation and Expansion.

Hey, even if you could map the rate of expansion, it doesn't necessarily point to a central point (assuming that such a thing exists), there's other reasons non uniform expansion could occur

[barx1963 (Malcolm)]

Originally Posted by mikesbytes

Thanks for the info guys, much appreciated.

There yah go, proof I'm a newbie, I've mixed up Inflation and Expansion.

Hey, even if you could map the rate of expansion, it doesn't necessarily point to a central point (assuming that such a think exists), there's other reasons non uniform expansion could occur

Mike
Going back to the balloon analogy, a being on any point on the surface of the balloon will see all the other points moving away, and the further away they are, the faster they appear to be receding, which will give the impression that they are at the centre. Of course that applies to all the points. Again this is analogous to us within 4 dimensional spacetime.
This analogy was used by Hawking in "A Brief History of Time" which although it is a bit dated nowadays (for example it doesn't cover the accelerating expansion of the universe) is still a good intro to many concepts central to cosmology for the layman.

Cheers

Malcolm

[mikesbytes (Michael)]

The balloon explanation of expansion is a good simplistic example, however it could mislead some to think that the majority of the galaxy's are on the edge on the universe with not a lot in the middle

Are there any other simplistic examples knocking around?